I have tried other bubble levels designed to fit into hot shoes but, quite honestly, they have been a waste of money compared to the slightly more expensive Lens Coat levels, which always fit snugly but not too snugly and produce consistent, accurate results, a real necessity when you're working with ball heads or geared heads or even plain old-fashioned pan/tilt tripod heads. I use the 2-axis levels with my Canon XA30 camcorder and the 3-axis levels with my Phase One 645DF and to a more limited extent with my Canon EOS-1 in the latter case when I'm working with film. In all cases, highly recommended!!!..